Dethreading attachment for stay-bolt machines.



s. L. GARY. DETHREADING ATTACHMENT FOR STAY BOLT MACHINES.

APPLICATION TILED JULY 21,1913.

1,1 31,364. Patented Mar. 9, 1915.

3 SHEETS-SHEET 1.

HIM

S. L. GARY. nsmmmnw ATTACHMENT FOR STAY BOLT monmss. APPLICATION FILED JULY 21,1913. 1,1 31,364. Patented Mar.9, 1915.

3 SHBETk-SHEET 2.

S. L. GARY. DETHREADING ATTACHMENT FOR. STAY BOLT MACHINES.

APPLICATION FILED JULY 21, 1913.

Patented Mar. 9, 1915.

3 SHEETSSHEET 3.

UNITED STATES PATENT OFFICE.

DETHREADING ATTACHMENT FOR STAY-BOLT MACHINES.

Specification of Letters Patent.

Patented Mar. 9, 1915.

Application filed July 21, 1913. Serial No. 780,259.

T all whom it may concern:

Be it known that I, SHIRLEY LACEY GARY, a citizen of the United. States, residing at South Richmond, in the county of Chesterfield and State of Virginia, have invented certain new and useful Improvements in Dethreading Attachments for Stay-Bolt- Threading Machines, of which the following is a specification.

This invention relates to machines for threading and then dethreading or reducing bolt blanks, and particularly to that form of machine for this purpose which is illustrated and described in Patent No. 913,520, granted to C. K. Lassiter, on February 23, 1909.

This machine is particularly designed for the purpose of threading and dethreading stay bolts of boilers. Each stay bolt has a screw threaded portion at opposite ends and the usual practice is to thread the entire length of the stay bolt and then dethread or reduce the middle portion of the bolt, that is remove the screw threads therefrom. The various stay bolts used in boilers are many in number and even for any one boiler, vary greatly in length. Thus, in a locomotive boiler there are from eighteen to twenty-six different lengths of stay bolts used.

In threading and dethreading boiler stay bolts, provision must be made for blanking or dethreading a distance along the bolts of from three inches to twenty-five inches, the sizes of the various bolts differing by quarter inches and the lengths of the dethreaded portions of the various bolts varying by quarter inches. It will therefore be seen that in ordinary practicethere are eightyeight different lengths of bolts and that these bolts have to be dethreaded for eighty-eight di lfcrcnt distances.

In the patent to Lassiter, above described, the stay bolt is rotatably mounted in a vertical position and a screw threaded die is forced downward on said bolt as it is rotated threading the bolt along its entire extent. The bolt is dethreaded between its ends and for the required distances by o ppositely disposed cutting tools which are forced into and out of engagement with the bolts by means of a pair of profile strips or controlling strips. This raises the number of profile strips required for ordinary practice to one-hundred and ninety-six, which number must be provided with the machine in order that the machine may operate upon all the various sizes of stay bolts commonly found. The provision of such a large number of profile strips is expensive and furthermore, whenever it is necessary to dethread a bolt of one size after working on a bolt of another size it is necessary to remove the profile strips already on the machine and replace them with new profile strips. This requires the removal and replacement of a number of screws, the adjustment of strips and the re-adjustment of the controlling rods on which the profile strips are mounted. This takes time and this means loss of money to the operator. These machines as placed upon the market are either six spindle machines or eight spindle. That is, the machine is capable of screw threading and blanking either six or eight bolts at a time, or screw-threading and blanking six or eight bolts of different lengths at a time, each spindle using a different pair of profile strips. Eight different pairs of strips are provided with each machine but these are not enough by onehalf for the threading and dethreading of the stay bolts for one boiler having eighteen rows of stay bolts of different lengths, and there would only be one-third enough profile strips for a boiler having twenty-five rows of stay bolts of different lengths. As a consequence, the manufacturer must provide himself with other sets of profile strips each relatively costly to make and requiring care in handling, and when the rows of bolts of different lengths necessary for different makes of boilers is considered it will be seen that the cost of making profile strips on all the various stay bolts liable to be used, amounts to a considerable sum. Furthermore, where a great many different lengths of profile strips are kept it is necessary that they shall be kept in regular order without displacement as otherwise it would be extremely difficult to locate a profile strip of exactly the right contour and length for any particular piece of work, and this requires great care and means also loss of time.

The primary object of my invention is the provision of a machine of the character above described wherein the necessity of using separate profile strips for each length of bolt is done away with, the machine being so constructed that only a simple adjustment is needed to adapt the machine to dethreading or blanking any length of stay bolt.

A further object of the invention is to provide a machine in which it is only necessary to set the die closing stop to its proper position in order to secure a proper adjust- 'ment of the machine to work upon any desired length of bolt.

Another object of the invention is the provision of dethreading controlling means which are adapted to be placed upon and used with any usual or ordinary make of stay bolt threading and reducing mechamsm.

Other objects will appear in the course of the following description.

My invention is illustrated in the accompanying drawings. wherein Figure l is a fragmentary front elevation of a machine constructed in accordance with my invention, showing one spindle of the machine and the co-acting parts thereof. Fig. 2 is an enlarged section on the line 2 2 of .Fig. 1. Fig. 3 is a section on the line 33 of Fig. 2, showing the screw threading dies in the position they occupy when moving'downward in the operation of the cutting or blanking tools. Fig. 4 is a like View to Fig. 3 but showing the position of the screw threading dies and cutting dies when they have arrived at the lowermost position and the cutting tools have been shifted out of engagement with the work. Fig. 5 a side elevation of the controlling bar and the yoke. Fig. 6 is a like view to Fig. 5 but showing the yoke in section. Fig. 7 is an end view of the parts shown in Figs. 5 and 6. Fig. 8 is a transverse section on the line S8 of Fig. 6. Fig. 9 is a transverse section on the line 9-9 of Fig. 6. Fig. 10 is a. diagrammatic view illustrating the operation of the blanking, tools.

Corresponding and like parts are referred to in the following description and indicated in all the views of the accompanying drawings by the same reference characters.

Referring to these drawings 2 designates a base of any suitable construction and of any suitable dimensions on which is supported a bed 3. The bed carries an oil-receiving ho per or receptacle 4 having an outlet pipe leading down therefrom, not shown, to an oil tank. Rising from the bed are oppositely d sposed uprights or standards 5, one of which is illustrated in Fig. 5, supporting at their upper ends an oil distributing tank 6. The oil from this tank flows through the tool carriage in a manner not necessary to describe herein and passes into the hopper4 from whence it again passes to a pump. pumping the oil to the reservoir 6 so as to provide for a continuous circulation.

Rising from the bed between the uprights 5 and attached to the bottom of the oil distributing tank 6 are a pair of guide rods 16 on which is slidably mounted a tool holding carriage designated generally 8. Fixed to the carriage and extending upwardly through the bottom of the tank 6 are operating rods 9 connected at their upper ends to a cross-head 10 having attached thereto one end of a carriage controlling belt 11. This beltpasses upwardly over and extends downwardly from a pulley 12 mounted upon a constantly rotating shaft 13. The shaft 13 is continuously rotated while the belt 11 is normally slack and rests loosely upon the pulley or band-wheel 12. Vhen, however, the operator draws downward upon the free end of the belt 11 he brings the belt into engagement with the wheel 12 and power will be applied to elevate the carriage. The weight of the carriage and that of the tools carried thereby is sutlicient to effect the downward feed of the tool-holding carriage by gravity, in which feed or movement the cutting and threading tools operate upon the bolt blank, the action of the threading tools on the blank regulating the movement J of the carriage at a proper prescribed speed.

A chuck 11 is rotatably mounted on the upper face of the bed and is driven by means of the shaft 15 to which power may be applied. This head or chuck 14 has a socket in it to receive a lug or projection formed on' the lower end of the bolt blank A. the blank being thereby supported and rotated in the operation of the machine.

At diametrically opposite points, with relation to the chuck 14, are disposed vertical guide rods 16, which are supported in any suitable manner, and slidably mounted upon these guide rods is the tool holding carriage, previously referred to. The details of this tool holding carriage is fully illustrated in the patent to Lassiter, No. 519,520 on F ebruary 23, 1909, and therefore these details need no description orillustration in this application. It is suflicient to say that the carriage is provided at opposite ends with the integral sleeve 17. through which the guiderods 16 pass and that supported in the lower portion of the carriage are the screw-cutting dies 18, these dies being adjustable to the size of the bolt blank so as to cut a deeper or shallower thread, in a manner described in said patent. Means are also provided in connection with such carriage whereby the screw-cutting dies may be shifted outward from the bolt blank or opened so as to permit the carriage to move up or down without engaging the bolt blank, and means are also provided for automatically closing the dies upon the bolt blank. The automatic mechanism whereby the closing and openin of the dies is accomplished is fully illus trated and descr ed in the prior patent to Lassitcr and made no description here. The

closing of the dies is secured by mechanism actuated by a finger 19 which projects upward and is adapted to come in contact with an adjustable finger-actuating stop 20 having the form of a bracket adjustable upon one of the guide rods 16. As illustrated this bracket is clamped on the guide rod 16 by means of a screw 21. The opening of the dies whenthe carriage has arrived at its lowermost position is secured by means of a stud 22 projecting from the carriage on the side opposite to the finger 19. This stud is adapted to engage with a suitable stop 23 mounted upon the lower end of one of the guides 16, as illustrated in Figs. '1 and 2. When the carriage arrives at the position where it is to commence work on the bolt, the finger 19 contacts with the stop 20 and the finger is actuated to close the dies 18 upon the work. lVhen the carriage has reached the lowest limit of its movement the stud 22 will come in contact with the stop 23 and the dies will be automatically opened so as to permit the carriage to travel back or upward upon the bolt without the dies engaging the same.

Disposed in the carriage 8 and movable therewith are the reducing cutters 25. These reducing cutters have sliding movement in the carriage and there are two of these outters disposed in diametrically opposite relation to each other. The extremities of each cutter 25 extends outward and is supported in a yoke 26 illustrated in plan view in Fig. 8, this yoke 26 being bolted or otherwise attached to the body of the carriage. The outer end of each of the cutting tools 25 has sliding engagement in an opening 27 formed in the yoke and each of the cutters is provided with a head 28 held in place upon the cutter by means of a set-screw 129. A spring 30 is disposed between this head 28 and the adjacent face of the carriage and urges the cutter outward. The head 28 has a laterally projecting stud 31 carrying a friction roller 32. The extremity of this stud 31 projects into a guide groove 33 formed on the inside face of one of the side members of the yoke 26 so as to prevent any deflection of the pin or stud 31. Passing through each yoke is a controlling bar 34.

There are two of these controlling bars for each of the cutters and each controlling bar extends vertically parallel to the corresponding guide or post 16. Each controlling bar is rectangular in cross section and relatively thin at the upper and lower ends of each controlling bar and reduced as at 35. The upper reduced end of the controlling bar 34 passes through an adjustable bracket 37 and is held in adjusted relation to this bracket by means of nuts 38. The lower end of each of the bars 34 passes through and is supported in a bracket 39 and is held in proper adjusted relation upon thls bracket by means of nuts 40. By adjusting these nuts 40 it is possible to raise or lower each of the bars 34, for a purpose which will be later stated. v

-The parts heretofore described are the same as those which are illustrated and described in the patent granted to Lassiter and heretofore referred to. As the construction and operation of these parts are well known in the art, no further description of these parts is deemed to be necessary.

My invention resides in the means whereby the tools 25 are forced inward into cutting engagemcnt with the bolt blank and automatically forced outward when the carriage 8 has reached the lower limit of its movement. In the patent to Lassiter. before referred to, the forcing inward of the cutter was secured by means of the profile strip 34 contacting with the stud 31. The profile strips were of such shape and length that after the screw-cutting dies had screw threaded the upper end of the bolt blank for a certain distance the dethreading tools 25 would be forced inward cutting away the screw threads and following immediately after the threading dies. At the lowest point of travel of the carriage these profile strips were reduced in width, thus permitting the springs 30 to force the cutting tools outward and away from the work, allowing the carriage to be drawn upward with the cutting tools and dies free from engagement with the work.

The objections to the use of profile strips of the character described in the said Lassiter patent have been heretofore fully stated. My invention consists in doing away with the profile strips, as described in the said patent and providing in place thereof a profile member 41 frictionally engaged with the cut controlling bars 34 but movable with the carriage after the carriage has traveled a certain distance. The construction of this profile member and its coaction with the carriage is best illustrated in Figs.- 5. 6 and 7 and the diagrammatic view of Fig. 10. The profile strip 41 consists of a piece of metal having the same thickness as the bar 34 and havin a flat inner face which bears directly against the edge face of the bar 34. The profile strip has a fiat outer face 42 for a portion of its length, which is parallel to the flat inner face and is then reduced to provide a Wedg ing portion 43, the extremity of this wedging portion being beveled as at 44 and the edging portion then extends parallel to the inner face and is then outwardly inclined as at 45. It is to be particularly noted in connection with the profile strip 41 that the bar 34 at its lower portion has a less width than the upper portion of the bar, the bar being reduced at the point 46 and having an inclined face joining the lower reduced portion of the bar to the 11pper portion of the bar.

The profile strip 41 is disposed in a rectangular recess 48 formed in a sliding block or slide 49, this recess being of such width that the sliding block snugly embraces the bar 34 but without too great a frictional engagement therewith. The profile strip 41 is held in this recess by transverse pins 47, the inner face of the profile strip being held snugly against the adjacent face of the bar 34 when the strip is moving along the unreduced portion of the bar as illustrated clearly in Fig. 6. When, however, the slide 49 is moved downward so far as to carry the profile strip down to the reduced portion of the bar 34, the profile strip will be out of close engagement with the edge of the bar 34.

For the purpose of holding the profile strip in snug engagement with the bar 34 and also for the purpose of frictionally engaging the slide with the bar 34, I provide mechanism illustrated most clearly in Fig. 6. Disposed within the recess 48 and bearing frictionally against the outer edge face of the bar 34 is a friction block or shoe 51 which is yieldingly urged against the edge face of the bar 34 as will now appear.

Disposed between the end wall of the slide 49 the outer face of the shoe 51 and spaced therefrom is a block 52. The adjacent faces of the block and shoe are recessed to provide for holding a coil spring Opposite portions of the shoe 51 and the block are formed with nearly cylindrical recesses 54 and disposed within these recesses 54 are the wedging members 55, each of these wedging members having at opposite ends the semicircular heads 56 which fit within the recesses 54. The block 52 is so disposed with relation to the shoe 51 that when these wedging members are turned into positions at right angles to the axis of the bar 34 they will exert a toggle action and wedge the shoe 51 against the edge face of the bar 34. When, however, these members are turned downward at an inclination to the axis of the rod 34, they will not exert this wedging action.

The spring 53 as will be noted from Fig. 6 is supported at its lower end upon a projecting portion of the block 52 while at its upper end this spring bears against a projection formed upon the shoe 51. As a consequence this spring acts to urge the wedging members 55 into a position where they will wedge the shoe 51 against the edge face of the rod 34 but the spring will yield to permit a movement of the shoe 51 downward with relation to the slide.

Passing through the rear wall of the slide is a screw 57 which passes loosely through this end wall but has screw threaded engagement with the block 52 so as to hold the block from vertical movement with relation to the slide but permit the block to move in and out. For adjusting the block 52 nearer to or farther from the rod 34 to thereby increase or decrease the frictional resistance of the device, I provide the screws 58 which pass through the end wall and bear at their inner ends against the outer edge of the block 52. These screws are held in adjusted position by means of lock nuts 59. Each screw is formed with a head 60 whereby it may be turned.

Attached to the slide 49 is a vertically extending supporting strap 61 of relatively thin sheet metal which is longitudinally slotted as at 62. The screw 63 projecting from the side of the yoke 26 passes through this slot 62 and the strap 61 has a vertical play upon the screw 63. Preferably the upper end of the strap is provided with an abutment 64 which'may be adjustable up or down within the slot 62 and which may be held in any suitable position by means of the screw 65.

It will be noted from Fig. 5 that the slot 62 is of such length that the carriage 8 and the yoke 26 will shift downward to such a degree that the roller 32 will engage with the wedge-like projection 43 of the profile strip just before the yoke 26 comes in contact with the upper face of the block 51 and that when the roller 32 comes in contact with the profile strip 43 the roller will be forced outward and will carry with it the cutting tool forcing the cutting tool into engagement with the work. While the profile strip 41 and the carriage are moving downward they will engage with each other over the unreduced portion of the bar 34 and the tool will be held in engagement with the work, but as soon as the profile strip 41 has passed the inclined portion 46 and arrived at the reduced lower portion of the bar 34, the profile strip will be forced outward and the corresponding tool will be forced outward by the spring 30 thereof so as to escape the work. Upon the upward movement of the carriage the carriage will first rise and only when it contacts with the upper end of the slot 62 or with the abutment thereat will the profile strip be raised so that when the carriage rises, the roller 32- will pass out of its engagement with the profile strip entirely and will not come in' contact with the strip until the carrier is again moved downward.

When the profile strip, the tool carrier and the slide are in the position shown in Fig. 6, the weight of the slide, 49 would act to shift the slide downward carrying with it the profile strip 43, but this is resisted by the wedging or toggle action of the members 56, the weight of the slide 49 acting to force the shoe 51 into close frictional engagement with the rear edge of the bar 34 and thus clamp the bar 34 between the shoe 51 and the strip 41. It will be noted that the shoe 51 is of such length that it projects above the upper face of the slide. Now when the tool carrier moves downward, the roller 32 will ride up on the incline 44 of the profile strip forcing the tool inward.

When the lower face of the yoke 26 engages with the upper end of the shoe 51, the weight of the tool carrier and the yoke will act to force the shoe 51 downward, thus relieving the pressure of the shoe upon the edge face of the rod 34 and reducing its frictional engagement therewith. The slide will still be held engaged with the rod 34 by the pressure of the spring 30 on the roller 32. The frictional engagement of the slide with the rod 34 having been reduced, the slide will move downward with the carriage until suchtime as the slide passes onto the reduced portion of the rod 34 when frictional engagement will be entirely relieved and the profile strip will move inward.

When the carriage rises, it will move upward independently of the slide until the screw 63 engages with the upper end of the slot 62. Then the carriage will draw upward on the slide. This upward movement is permitted because the contact of the face of the rod 34 with the shoe 51 will cause the shoe to move downward, relieving the frictional engagement between the shoe. and the slide. It will be obvious, however, that as soon as any lifting movement on the slide is ended, the weight of the slide will cause the shoe 51 to be forced inward and the slide held at the position to which it was lifted until the carriage again moves downward so that the yoke 26 is brought in engagement with the upper end of the shoe 51.

If it is desired to increase the pressure of the shoe 51 upon the slide this is secured by turning in the screws 57.

The operation of my invention will be plain from Figs. 3 and 4 and from Fig. '10. The stop 20 is of course to be disposed at a height upon the guide 16 somewhat greater than the height of the bolt to be threaded. The carriage is shifted upward by means of the hand pull 11 until it is raised to such position that the bolt blank A will be inserted in the chuck 14. As soon as the bolt blank is inserted and is rotated, the carriage is allowed to move downward upon the bolt blank. At the commencement of this downward movement the cutters 25 are out of engagement with the bolt blank but the threading dies 18 are in engagement with the bolt blank and cut the threaded portion a (see Fig. 10). During this time the slide 41 is held frictionally upon the bar 31 and of course is not moved downward by reason of the slotted strap 62. The slot in this strap is approximately the length of the threaded portion a of the bolt. When, however, the carriage has descended sufliciently to permit the engagement of the rollers 32 on the tool shanks with the profile strips, the tool will be moved inward against the work, and as soon as this inward movement of the tool has been secured, the under face of the yoke 26 will have contacted with the upper face of the slide 49. The weight of the descending carriage will now release the frictional resistance of the shoe 51 and will carry the slide downward with the profile strips in engagement with the corresponding roller 32. This will continue until, as before described, the slide 49 has passed the point 46 when, as before stated, the slide will move outward carrying with it the profile strip and the spring 30 and forcing the corresponding tool outward and away from the work. The tools 25 will have by this time formed the reduced or dethreaded portion 1), as shown in Fig. 10, and after the tools 25 have been thrown out of engagement with the blank, the screw threading dies will continue to thread the lower portion of the blank 0 (see Fig. 10). As soon as the blank has been completed to form a stay bolt the lifting strap 11 is tightened whereby the pulley 12 will cause the strap to lift upward upon the carriage, elevating it. As before stated, when the carriage moves upward the yoke screw 63 travels upward through the slot 62 of the strap 61 and the profile strip 41 is therefore left behind. When the screw 63 reaches the end of the slot 62, however, then the profile strip and the slide within which it is mounted travels upward with the carriage, as before described. When the carriage has reached its lowermost position, as previously stated, the jaws of the thread ing dies are opened, permitting the removal of the completed stay bolt and the introduction of a new blank. The jaws of the threading dies open upon the upward travel of the carriage until the member 19 on the carriage engages with the stop 20, where upon the threading dies are automatically closed upon the bolt blank and work begins.

It will be seen that the extent of the dethreading may always be regulated by adjusting the stop 20 with relation to the beginning 46 of the reduced portion of the bar 34 and that the length of the stay bolt and the amount of this reduced portion is only limited by the height to which the stop 20 may be shifted upon the guide 16. It is of course necessary, sometimes to adjust the controlling bar 34 in order to vary the height at the point of the dethreading ends so as to increase or decrease the length of the screw threaded extremity 0 of the stay bolt. This is accomplished by adjusting the bars 34 within the brackets 37 and 39 and holding them adjusted by means of the nuts 40. The distance to which the portion a of the bolt may be threaded before the profile strips throws the dethreadin cutters into operation may also be adjuste by adjusting the abutment 64 with relation to the strap 61, it being obvious that when the stop 64 is adjusted at the extreme upper end of the strap 61 the dethreading tool will be thrown into operation much later than if the abutment be lowered with relation to the slide 49.

The operation of my invention will be obvious from what has gone before, and particularly from Fig. 10, which as before stated, is a diagrammatic view showing the threading dies, the cutting tools, the controlling rods or bars and a bolt partially threaded and partially dethreaded. In Fig. 10 the upper end a of the stay bolt has been threaded. In dotted lines is shown the position of the profile strip 42 and the position of the wedge-shaped portion 43 when the dethreading operation has begun. The full lines show the position of the profile strip when the dethreading operation is half completed. The dotted lines of the lower portion of Fig. 10 show the position of the profile strips when the dethreading operation is stopped and the dethreading tools retracted, the remainder of the bolt 0 being threaded in the same manner as is the portion a. A

In the operation of the invention the stop 20 is first adjusted about two and one-half inches above the top of the bolt a which is supported within the chuck 14. The carriage 8 is in its lowered position. As soon as the proper adjustments are made the carriage 8 is raised by drawing downward upon the band 11 which causes the pulleys 12 to frictionally engage the band to raise the carriage. \Vhen the carriage reaches the stop 20 the cutting dies will be contracted upon the bolt and the band 11 is then released. The weight of the carriage causes it to move downward, the cutting dies continuously threading the bolt. As the carriage moves downward it has sliding engagement with the strap 61 until the rollers 32 carried by the cutting tools engage the inclination 44 of the profile strip. The rollers are then moved inward upon a continued descent of the carriage and the cutting tool will be forced inward to dethread the heretofore threaded portion of the bolt.

As soon as the yokes 26 have engaged theupper faces of the sliding blocks 49 the slides 49 will be caused to move downward with the yoke, the tools being at this time held in their projected position and the tools will be held projected until the slides 49 pass onto the contracted portions of the bars 34. lVhen this occurs the springs 30 will act to force the tools outward and will force outward the profile strips 41 and the slides to the position shown in Figs. 4 and 10, withdrawing the cutting tools from engagement with the bolt. By this time the cutting dies have nearly completed their work. When the threading is completed the bolt is removed and a new bolt put in place.

It will be seen that a machine equipped with my improved form of profile strip will be able to work upon any length of bolt for any size of boiler, and when used it will save for the purchaser or owner from $500 to $1000 a year spent in time and material used in making, taking off and replacing profile strips of different lengths and re setting the master strip or controlling strips. There is not only an initial saving to the manufacturer in the disuse of profile strips but there is the further saving to the user in time and money. Furthermore it will be seen that my invention is very simple, can be applied to machines now on the market at a relatively small cost, may be readily adjusted and affects a great saving as well as making one machine capable of working on all lengths of bolt.

While I have illustrated in Fig. 1 a machine having only one spindle, it will be understood that machines may have as many spindles as desired and that my devices will operate just as well upon a machine having eight spindles as they will on a machine having one, there being of course two profile strips 41 and related mechanism to each spindle.

Having thus described the invention what is claimed as new is 1. In a machineof the character specified embodying blank holding and rotating means, mechanism for forming screw threads upon the blank, means movable with the screw thread forming mechanism for reducing the blank intermediate its threaded ends, means for automatically throwing the screw threading mechanism into and out of action, and other means for throwing the blank reducing mechanism into and out of action at predetermined periods, such means embodying a profile element mounted to move with the screw thread-forming mechanism during a portion of the travel of such mechanism.

2. In'a machine of the character specified embodying blank holding and rotating means, mechanism for forming screw threads upon the blank, means movable with the screw thread forming mechanism for re ducing the blank intermediate its threaded ends, means for automatically throwing the screw threading mechanism into and out of action, and other means embodying a profile element movable with the screw thread forming and reducing mechanisms for a part of their travel only for "throwing the blank reducing mechanism into and out of action at predetermined periods- 3. In a machine of the character specified embodying blank holding and rotating means, mechanism for forming screw threads upon the blank, means movable with the screw thread forming mechanism for reducing the blank intermediate its threaded ends, means for automatically throwing the screw threading mechanism into and out of action, actuating means for the reducing mechanism embodying a movable element for positively throwing the said reducing mechanism into and out of operation at predetermined intervals, and connecting means between the said actuating means and the thread forming and reducing mechanisms embodying relatively movable parts to admit of the said actuating means moving part way with the thread forming and reducing mechanisms.

4. In mechanism of the character specified embodying blank holding and rotating means, a carriage, mechanism mounted upon the carriage for forming screw threads upon the blank, mechanism for reducing the blank also mounted upon the said carriage, means for throwing the screw thread forming mechanism into and out of action, actuating means embodying a movable profile element for throwing the blank reducing mechanism into and out of action and connecting means between the said carriage and movable profile element comprising relatively movable parts to admit of the carriage having a greater travel in each direc tion than the said movable profile element.

5. In mechanism of the character specified embodying blank holding and rotating means, a carriage, mechanism mounted upon the carriage for forming screw threads upon the blank, mechanism for reducing the blank also mounted upon the said carriage, means for throwing the screw thread forming mechanism into and out of action, a guide parallel with the line of travel of the carriage, a profile element slidable upon the guide adapted to operate the blank reducing mechanism, and connecting means between the said carriage and the profile element.

(3. In mechanism of the character described, means for holding and rotating a bolt blank, a threading die movable along the blank, a dethreading tool movable with the die, means normally holding said tool out of engagement with the blank, a controlling bar extending parallel with the blank, :1 profile member frictionally supported upon the controlling bar for sliding movement and adapted to be engaged by the tool to cause a movement of the tool into cutting position, said profile member being moval'ile with the die and cutting tool along the blank, and means disposed at the lower end of the controlling bar permitting the outward shifting of the profile member and the tool.

7. In a machine of the character specified embodying blank holding and rotating means, mechanism for forming a screw thread upon the blank, mechanism for reducing the blank and movable with the screw thread mechanism, means for throwing the screw thread forming mechanism into and out of action, a guide arranged parallel with the blank and line of travel of the screw thread forming and blank reducing mechanisms, means for operating the blank reducing mechanism slidable upon the guide, means for securing the blank reducing operating means to the guide and connecting means between the blank reducing operat ing means and the said screw thread forming and blank reducing mechanisms and comprising relatively movable parts to permit of a variable travel.

8. In a machine of the character set forth and in combination with means for holding and rotating a blank, a carriage, blank threading and reducing mechanisms mounted upon said carriage, means for throwing the blank threading mechanism into and out of operation, a guide parallel with the line of travel of the carriage, a profile member slidable upon the guide adapted to actuate the blank reducing mechanism and connecting means between the profile member and the carriage comprising relatively movable parts to permit of the carriage having a greater movement in each direction than the profile member.

9, A machine of the character specified, the combination of means for holding and rotating a blank, blank threading and reducing devices, a carriage receiving the blank threading and reducing devices, operating means for throwing the blank threading mechanism into and out of action, a guide parallel with the line of travel of the carriage, a profile member slidable along the guide, means for securing the profile member to the carriage 'and connecting means between the said guide and the pro file member comprising relatively movable parts to permit of the carriage having a greater length of travel than the profile member.

10. In mechanism of the character described, means for holding and rotating a blank. a carriage movable along the blank, threading dies mounted on said carriage, a dethreading tool shiftably mounted upon the carriage and operating successively to the threading dies, means urging said tool out of cutting engagement with the blank. a controlling bar extending parallel to the blank, a slide on the controlling bar having irictional engagement therewith. and disposed in advance of and in the path oi movement of the carriage, a loose connection between the slide and the said carriage. and a profile strip mounted on the slide and engageable with said tool to force it inward when the slide and carriage engage with each other for common movement along the blank.

11. In mechanism of the character described, means for holding and rotating :1. blank, a carriage movable along the blank, a tool shiftably mounted in said carriage, means urging the tool out of cutting engagement with theblank, a controlling bar, one end of said bar being reduced in Width, a slide shiftable along but frictionally engaged with said bar, a loose connection between the slide and carriage, and a profile strip mounted on the slide and engageable with the tool to force it inward when the slide and carriage are engaged for common movement along the bolt blank.

12. In a machine of the character set forth, the combination of a carriage, a cutting tool mounted upon the carriage and movable thereon in a direction at a right angle to the movement of the carriage,means yieldably pressing the cutting tool outward, a guide arranged parallel with the line of travel of the carriage, a tool operating member slidable upon the guide and adapted to engage the cutting tool to move the same against the yildable means normally exerting a pressure thereon, means for securing the tool operating member to the guide and means adapted to be actuated by the carriage for actuating the tool operating means.

13..In mechanism of the character described, means for holding and rotating a blank, a carriage movable along the blank, a cutting tool shiftably mounted in the carriage, means for urging the tool out of cutting engagemcnt with the blank. :1 controlling bar extending parallel to the blank. a slide mounted on the controlling bar and frictionally engaged therewith, a slotted member connecting the slide with the carriage. means on the carriage engaging said member through the slot thereof to permit an independent movement of the carriage relative to the slide for thelength of said slot. and a profile strip mounted on said slide and engaging the inner edge of the controlling bar and operatively engaging the tool to urge it into cutting engagement with the blank upon an engagement of the carriage with the slide for common movement along the blank.

14. In mechanism of the character described. means for holding and rotating a blank. a carriage movable along the blank, a blank cutting tool shiftably mounted in the carriage. means urging the tool out oi cutting ei-igagement' with the blank. a controlling bar extending parallel to the blank, a slide mounted on and frictionallv en gaging the controlling bar. a loose connection between the slide and the ci'irriage to permit a limited movement of the slide. the slide being disposed in the path of movement of the carriage, and a profile strip mounted upon said slide and engaging the inner face of the controlling bar, said profile strip being generally wedge shaped and adapted to force the cutting tool into engagement with the blank upon engagement between the carriage and the slide.

15. In mechanism of the character de scribed, means for holding and rotating a blank, a carriage movable along the blank, a blank cutting tool shiftably mounted in the carriage, means urging the tool out of cuttingengagement with the blank, a vertically adjustable controlling bar extending parallel to the blank and reduced in width near its lower end, a slide mounted on and frictionally engaging the controlling bar, a loose connection between the slide and the carriage to permit a limited movement of the slide, the slide being disposed in the path of movement of the carriage, and a profile strip mounted upon said slide and engaging the inner face of the controlling bar, said profile strip being generally wedge shaped and adapted to force the cutting tool into engagement with the blank upon engagement between the carriage and the slide.

16. In mechanism of the character described, means for holding and rotating :1 bolt blank, a carriage movable along the bolt blank, a cutting tool shiftably mounted in the carriage, means urging the cutting tool out of cutting engagement with the blank, a controlling bar extending parallel to the path of movement of the carriage, the lower portion of said controlling bar being reduced in width, a slide mounted on the controlling bar and frictionally engaged therewith. a loose connection between the slide and the carriage permitting an independent move ment of the carriage for a predetermined distance, said slide being disposed in the path of movement of the carriage and adapted to be engaged therewith after the carriage has moved a predetermined distance to cause a common movement of the slide and carriage, and a profile strip supported in the slide and engaging against the edge face of the controlling bar and adapted to operativelv engage the tool upon the engagement of the carriage and the slide to cause the tool to move into cutting engagement with the blank.

17. In mechanism of the character described, a vertically disposed rotatable spindle. means thereon for holding a blank, a vertically movable carriage adapted to surround the bolt blank. a cutting tool shittably mounted in the carriage, means urging the cutting tool out of engagement with the bolt blank, a controlling bar extending par allel to the spindle. a slide frictionally engaging the controlling bar and disposed in the path of movement of the carriage and face of the controlling bar, said profile strip being disposed in the path of movement of the outer end of said tool and being formed to shift the tool inward into cutting engagement with the blank upon an engagement of the carriage with the slide.

18. In mechanism of the character de-.

scribed, means for supporting a blank, a carriage, a shiftable blank cutting tool mounted in the carriage, means urging the cutting tool out of its engagement with the blank, means for relatively rotating the blank and tool, a controlling bar extending parallel to the blank, a slide frictionallyengaged with the controlling bar and projectj mg into the path of movement of the carriage, means for relatively shifting the carriage with relation to the slide and with relation to the blank, and a profile strip carried upon the slide and engaging with the 1 tool to force it into cutting engagement with the blank when the carriage and slide engage With each other for common movement.

19. In mechanism of the character described, a rotatable vertically disposed spindle, a chuck thereon adapted to support a vertically disposed blank, a guide extending parallel to the blank, a carriage slidable on said guide and adapted to embrace the blank, thread cutting dies mounted on the carriage and engaging the blank, a shiftable threading tool mounted on the carriage above the cutting dies, means urging said tool into cutting engagement with the blank, a controlling bar extending parallel to the blank, a slide mounted on said controlling bar and frictionally engaged therewith, a loose connection between the slide and the carriage permitting an independent downward movement of the carriage relative to the slide for a predetermined distance, and an upward movement of the carriage relative to the slide for a predetermined distance, and an approximately wedge-shaped profile strip mounted on the slide and disposed in the path of movement of the rear end of the tool and engageable with said tool to cause the shifting of the tool into cutting position.

20. In mechanism of the character described, means for holding and rotatin a vertical bolt blank, a vertically mova ile carriage adapted to surround the bolt blank, thread cutting dies mounted on. said carriage, oppositely disposed cutting tools mounted upon the carriage above the thread cutting dies, means urging said tools outward out of engagement with the blank, oppositely disposed vertical controlling bars passing through the carriage, slides mounted one on each controlling bar and frictionally engaged therewith, said slides being disposed in the path of movement of the carriage, a slotted connecting member extending upward from each slide and having loose engagement with the carriage at its end, and an approximately wedge shaped profile member mounted on each slide and bearing against the inner face of the corresponding controlling bar and disposed in the path of movement of the outer endof the corresponding tool whereby to shift said tool inward upon engagement of the rear end of the tool with the profile member.

21. In mechanism of the character described, means for holding and rotating a bolt blank, in a vertical position, oppositely disposed guides on each side of said means, a carriage mounted on said guides and adapted to surround the bolt blank and move downward or upward therealong, thread cutting dies mounted on the carriage, said dies being movable into and out of engagement with the bolt blank, shiftable tools mounted on the carriage above the blank, means urging said tools outward away from the bolt blank, oppositely disposed controlling bars extending parallel to the path of movement of the carriage, each controlling bar being reduced in width near its lower end, a slide on each controlling bar having frictional engagement therewith and disposed in the path of movement of the carriage, a loose connection between each slide and the carriage whereby to permit the carriage to have a movement independent of the slide for a predetermined extent, profile strips mounted one on each slide and engaging the edge face of the corresponding controlling bar, means disposed at the lower end of the path of movement of the carriage for causing the opening of the thread cuttin dies, means for raising the carriage, and a justable means disposed at the upper end of the path of movement of the carriage operatively engaging the thread cutting dies to close the same upon the bolt blank.

22. In mechanism of the character described, means for holding and rotating a blank, a carriage movable along the blank,

a blank cutting tool shiftably mounted in the carriage, means urging the tool out of cutting engagement with the blank, a controlling bar extending parallel to the blank, a slide mounted on the controlling bar, a loose connection between the slide and the carriage to permit a limited movement of the slide relative to the carriage, the slide being disposed in the path of'movement of the carriage, a profile strip mounted upon the slide and engaging the inner face of the controlling bar, said profile strip being preferably Wedge-shaped and adapted to force the cutting tool into engagement with the blank upon engagement between the carriage and the slide, a shoe mounted in the slide and engaging the controlling bar opposite to the profile strip, and means acting upon a vertical movement of the shoe relative to the slide for Wedgingthe shoe against the controlling bar but permitting an outward movement of the shoe away from the controlling bar upon a movement of the shoe downward relative to the slide.

23. In mechanism of the character described, means for holding and rotating a blank, a carriage movable along the blank, a blank cutting tool shiftably mounted in the carriage, means urging the tool out of cutting engagement with the blank, a controlling bar extending parallel to the blank, a slide mounted on the controlling bar, a loose connection between the slide and the carriage to permit a limited movement of the slide relative to the carriage, the slide being disposed in the path of movement of the carriage, a profile strip mounted upon the slide and engaging the inner face of the controlling bar, said prolile strip being preferably wedge-shaped and adapted to i'orce the cutting tool into engagement with the blank upon engagement between the car riagc and the slide, a vertically movable she; in inled in the slide and. engaging the l f bar opposite to the profile strip g members pivotally connected to the shoe and operatively connected to the slide a ting to shift the slide inward upon an up vard movement of the shoe relative to the slide out carrying said shoe inward upon a downward movement of the shoe relative to the slide, and a spring urging said s? ,e upward,said shoe projecting above the and being disposed in the path of the sl ill-r l 5i i the carriage Elie hanism olf the character defor holding and rotating a b a c mo able along the blank, a blank L't-latllig tool shiftably mounted in the carriage, means urging the tool out of cut ting engagement with the blank, a controlling bar extending parallel to the blank, a slide mounted on the controlling bar, a loose conno ion between the slide and the car 5e riage to permit a limited movement of the disposed in the path of movementof the carriage, a profile strip mounted upon the slide and engaging the inner face of the controlling bar, said profile strip being preferably wedge-shaped and adapted to force the cutting tool into engagement with the blank upon engagement between the carriage and the slide, a vertically movable shoe mounted on the slide and bearing against the edge face or" the controlling bar opposite the strip, said shoe normally projecting above the slide and being disposed in the path of movement of the carriage, an inwardly shiftable block mounted on the slide parallel to the shoe, pivoted wedging members extending between the block and the slide, a spring acting to force the slide upward and cause it to beiwedged against the controlling bar but permitting the shoe to move downward and out of close engagement with the controlling bar, and screws passing through the rear end of the slide and engaging said block whereby to adjust the block toward or from the controlling bar.

25. In mechanism of the character described, means for holding and rotating a blank, a carriage movable along the blank, a tool shiftably mounted in said carriage, means urging the tool out of cutting engagement with theblank, a controlling bar extending parallel to the blank, a slide loosely supported from. the carriage and disposed in the path of movement of the carriage, a profile strip mounted upon. said slide and engaging the inner face of the controlling bar, and means frictionally engaging the slide with"said controiiing bar, said means being shifted into inoperative position upon an engagement of the car riage with the slide and said means permit ting a relatively free upward or downward movement of the slide.

In testimony whereof I aflix my signature in presence of two witnesses.

SHIRLEY L. GARY.

Witnesses F. B. Moss, A, W. OTEY. 

